This invention relates to a device for balancing, holding and releasing a rake arm in a hay rake and, more particularly, relates to a device able to move and balance a rake arm of a hay rake between an operative position (in which the rake arm, provided with a plurality of tine rake wheels, is in a lower position to make the wheels to nearly touch the ground), and a non-operative position (in which the rake arm is in an upper position to permit easy transport and/or storage of the hay rake), to hold said rake arm in said upper position and to release the same arm from this upper position to return to the lower operative position, when needed.
Hay rakes are well known devices utilized in agriculture to aerate cut crops and merge them into windrows of various widths to facilitate the following collection and storage of the crops. Hay rakes typically utilize banks of rotating tined wheels mounted onto rake arms connected to a towed cart. In operation, such rake arms are angled with respect to one another in order to assume a V or a Y form to collect cut crop and form a windrow. Examples of hay rakes are disclosed, for instance, in the following documents: Canadian patent 2515979; Canadian application 2004 2477059; US Patent Application Publications 2002/0069634, 2005/0284126, and 2005/0144925; and in U.S. Pat. No. 7,318,312.
Rake arms can be very long in order to accommodate large banks of wheels and to permit a lesser number of passes to rake a field and hence to save time. However, long rake arms are obviously heavy and cumbersome and require further attention and improvements to avoid inconveniences both in operation and in transport. For example, in operation the rake arms are usually in a generally horizontal position and must be balanced to avoid pushing the tined wheels against the ground. This balancing is usually obtained by means of elastic masses (blocks of rubber or the like, springs, and so on) which support the weight of the rake arms. Vertically operating elastic masses may be utilized, which for a number of reasons are of limited length and hence of limited utility in supporting the rake arms. Above-cited U.S. Pat. No. 7,318,312 utilizes an horizontal spring to avoid the above drawback, acting between the towing cart and a pivoting arm utilized to rise and lower the rake arm. However, this approach requires additional parts to be acquired, stored, and mounted with attendant costs.
Thus, while various rake arm approaches have been proposed, they have not proven satisfactory for all situations. Accordingly, there remains a need for alternative rake arm approaches.